Commonly, headrest angles of a sofa can be adjusted to meet the requirement of customers and improve sofa comfort. Generally, such a design is achieved by providing a hinge for connecting the headrest inside a sofa and changing headrest position. Concretely, the headrest is pulled to drive the headrest and an end of hinge to rotate together. After the headrest rotates relative to the sofa body by a certain angle, the headrest is located in another position and the hinge positions it. This design allows consumers to adjust the headrest position according to their own needs. However, the headrest in this design must be pulled manually, and the operation is inconvenient.
At present, many sofas are equipped with an electric support system, which uses a built-in motor as a power source to adjust automatically a headrest angle. The electric support system generally includes two fasteners respectively fixed to the sofa body and the headrest, and a connecting rod assembly is connected between two fasteners. The connecting rod assembly includes two linear rods respectively pivoted to the headrest fasteners and pivot positions on the first fastener are separated. When the headrest is adjusted to a highest position, the two linear rods will be exposed between the sofa body and the headrest. Thus, the two exposed linear rods have a negative impact on an overall appearance of the sofa.
Thus it's necessary to provide an electric support system for steadily adjusting a tilting angle of a sofa headrest and reducing exposed area of connecting rods between a sofa body and a headrest.